分子印迹电化学传感器检测鸡肉、鱼肉和牛奶中磺胺二甲基嘧啶残留

Detection of sulfamethazine residues in chicken,fish and milk by molecularly imprinted electrochemical sensor

目的 将分子印迹技术与电化学相结合,建立分子印迹电化学传感器测定鸡肉、鱼肉和牛奶中磺胺二甲基嘧啶残留的分析方法。方法 以玻碳电极为基底,以导电聚合物聚3,4-乙烯二氧噻吩对其进行增敏处理,采用分子印迹技术结合原位电化学聚合形成分子印迹薄膜,对电极的修饰方法、修饰时间、聚合液中功能单体与模板分子比例进行了优化,并利用方波伏安法和阻抗法表征电极修饰情况。结果 电极经修饰后11 min即可达到吸附平衡,印迹电极对模板分子磺胺二甲基嘧啶的吸附能力远大于非印迹电极,选择性实验表明印迹电极具有良好的选择性。将合成的磺胺二甲基嘧啶分子印迹电化学传感器用于鸡肉、鱼肉和牛奶中磺胺二甲基嘧啶残留量检测,方法的线性范围为5~1000μg/L,r>0.99,实际样品添加回收率为71.92%~103.72%,检出限为0.406μg/L。结论 建立的分子印迹电化学传感器具有分子印迹的特异性选择与电化学的灵敏度,检测结果满足国家标准定量分析检测要求,方法简单、快速,为磺胺类药物检测提供了新的手段。

Objective To combine molecular imprinting technique with electrochemistry,and establish an analytical method for the determination of sulfamethazine residues in chicken,fish and milk by molecularly imprinted electrochemical sensors.Methods The glassy carbon electrode was used as a substrate and sensitized with a conducting polymer,poly-3,4-ethylenedioxythiophene,and molecularly imprinted films were formed by molecular imprinting technique combined with in situ electrochemical polymerization,and the modification method,modification time,and the ratio of functional monomer to template molecules in the polymerization solution of the electrode were optimized.The electrode modification was characterized by square wave voltammetry and impedance methods.Results The adsorption equilibrium time of modified electrode was 11 min.The adsorption capacity of the imprinted electrode for the template molecule sulfamethazine was much larger than that of the non-imprinted electrode,and the selectivity experiments showed that the imprinted electrode had good selectivity.The synthesized sulfamethazine molecularly imprinted electrochemical sensor was used for the determination of sulfamethazine residues in chicken,fish and milk.The linear range of the method was 5-1000 μg/L with r~2>0.99.The recoveries of the actual samples spiked were 71.92%-103.72% and the limit of detection was 0.406 μg/L.Conclusion The established molecularly imprinted electrochemical sensor has the specific selection of molecular imprinting with the sensitivity of electrochemistry,and the detected results meet the requirements of national standards for quantitative analysis and detection,and the method is simple and rapid,which provides a new means for the detection of sulfonamides.